Apparatus for heating gaseous materials



Aug. 27, 1963 Ml U. CLAUSER ETAL APPARATUS FOR HEATING GASEOUS MATERIALS Filed Dec. 12, 1958 2 Sheets-Sheet 1 PLAS MA Aug. 27, 1963 M. U. cLAusER ETAL 3,102,088

APPARATUS FoR HEATING GAsRous MATERIALS Filed Dec. l2, 1958 2 Sheets-Sheet 2 United States Patent O 3,102,088 APPARATUS FOR PEATING GASEOUS MATERIALS Milton U. Clauser, Rolling Hills, Rudolf X. Meyer, aciiic Palisades, and Richard H. Huddlestone and Burton D. Fried, Los Angeles, Calif., assignorsaby mesne assignments, to Space Technology Laboratories, Inc., El Segundo, Calif., a corporation oi Delaware Filed Dec. l2, 1958, Ser. No. 730,156 11 Claims. (Cl. 20d-4193.2)

This invention relates in general to the magnetohydrodynamics art and more particularly to a new and improved system for the nonadiabatic heating of gaseous materials by means of the pinch eilect.

In the investigation of thermodynamic processes, as well as in the generation of high energy particles for research and other purposes, it is necessary to accelerated the particles of a gaseous material to a kinetic energy level corresponding to a very high temperature. Since the temperatures at which neutrons are generated are eX- tremely high, being of the order of 108 Kelvin, conventional heating arrangements cannot be employed. However, by accelerating the particles of the gaseous material to a high kinetic energy corresponding to a giventtemperature, magnetohydrodynarnic investigations may be` conducted even though a thermal equilibrium is not established. Accordingly, throughout the following descriptionthe terms temperature and heat shall be taken to mean the corresponding levels or increases in kinetic energy of the particles of the gaseous 'material whether` or not thermal equilibrium is established or sustained.

ln one known arrangement for accelerating particles of a gaseous material to ahigh kinetic energy level, an electrically conductive gas, which may be referred to as a plasma, is conried within a tube and a shock wave is generated at one end of the tube which travels along the tube accelerating the gas particles at the interface between the traveling shock wave and the plasma. Thus, the shock wave functions in -a manner similar to a piston with each particle acquiring a `velocity comparable to the piston velocity. However, as the shock wave travels down the tube, a fairly rapid attenuation takes place so that the shock Wave gradually slows down, with the result that kinetic energies of the gas particles corresponding to extremely high temperatures are not achieved.

An additional disadvantage of known `arrangements of shock tubes for producing high kinetic energy gas particles is that heated gaseous material is in Contact with the side walls of the tube which may, therefore, be expected to deteriorate. More specifically, at the temperatures under consideration, some of the surface material of the walls will become evaporated, thereby contaminating the gaseous particles being accelerated. A detailed! description `of the production of high kinetic energy gas particles through the use of shock waves may be found in a series of articles under the heading Magnetically Driven Shock Waves, commencing at page 75 of a symposium entitled Magnetohydrodynamics, published by .the Stanford University Press in 1957, as well las in an article in the Physical Review, vol. 107, No. 2, luly 15, 1957, pp. 345-350.

An alternative arrangement for imparting high kinetic energies to the particles of an electrically conductive gas is that in which a discharge tube is arranged to receive a quantity of ionized gas, a high density current then being passed through the gas within the discharge tube. The current passing through the electrically conductive gas establishes magnetic fields which function to constrict or drive the gas particles towards the center of the discharge tube along a central axis parallel to the direction of current ow. The phenomenon by which the magnetic fields function to drive the gas inwardly is referred to as the pinch effect and has` long vbeen observed in the tendency of fluid met-al conductors to pinch oil when carrying high currents. A detailed description of the phenomenon may be found in van article by Rosenbluth Dynamics of` a Pinched Gas, appearing at page 57 of :a symposium entitled Magnetohydrodynamics, published by the Stanford University Press in 1957. t

ln known arrangements for achieving the pinch effect through the passage of high density currents in a discharge tube containing electrically conductive gas, a high density current pulse is generally derived by quickly discharging one or more highly charged capacitors through the gas. However, the density of current discharge is limited bythe inductance of the lead wires between the capacitor and the discharge tube, as well as by the delay encountered as a result of the transit time for energy traveling from the far reaches of the capacitor to the discharge tube so that in known arrangements gas particles have not been accelerated to kinetic energy levels at which proper investigations of thermonuclear reactions may be made. ln addition, the presence of electrical conductors and/ or capacitor plates charged to high volt-A age levels makesthe operation of known `arrangements hazardous and leads to undesirable corona discharge eiects.

Accordingly, it is a principal object of the present invention to provide new and improved apparatus for imparting kinetic energy to gas particles.l

It is an additional object of the present invention to provide new and improved apparatus for accelerating gas particles to high kinetic energy levels by means of the pinch etect.

It is yet another object of the present invention to provide apparatus `for substantially reducing the delay in passing la high density current pulse through an electrically conductive gas.

lt is still another object of the present invention to profor shortening the discharge time involved in discharging a capacitor through a discharge tube to obtain a high density current therein.

The present invention overcomes the above and other disadvantages and limitations encountered in prior art apparatus vby disposing a discharge tube between the plates of a capacitor in such a manner that energy may be passed isotropic'ally and omnidirectionally from the capacitor through the discharge tube. According to a basic concept of the present invention, la discharge tube is disposed relative to a capacitor such that the energy contained in the field of the capacitor is directed through the discharge tube along the most abbreviated path possible between the capacitor and tube. In accordance with the stated concept, a discharge tube may be mounted between the plates of a capacitor and symmetrically with respect thereto.

More particularly, according to an embodiment Iof the invention, an inner cylindrical capacitor plate is coaxial-ly arranged within an outer cylindrical capacitor plate with the idischarge tube being disposed between the capacitor pilates in a region substantially equidistant from the ends of the plates so that stored energy in the peripheral regions .of the capacitor arrives at the discharge tube at substantially the same time. A switching device is connected between the rdischarge tube and one of the cylindrical capacitor plates so that the capacitor may be selectively ydischarged through the discharge tube. A

. through the discharge tube at the optimum time.

shock tube is arranged to ionize the gas utilized and drive it into the discharge .tube with a sequence timing arrangement being included to trigger automatically the switching' device to-initiate the discharge of the capacitor by the use of coaxial capacitor plates, the outer capacitor plate may be held at ground potential and the isolated inner capacitor plate charged so as to achieve safety in ,operation and absence of corona discharge.

A betterunderstanding of the invention may be had from a reading of the following detailed description and n an inspection lof the drawings, in which:

FIG. 1 is a diagrammatic illustration ofthe currents and magnetic fields which produce the' pinch effect;

FIG. 12 is a diagrammatic illustration of one LVform of apparatus in accordance with the invention;

FIG. 3 is a perspective viewof a portion of a preferred f capacitor discharge system in accordance with the invention; 1 Y

FIG. 4 is a fragmentary View taken along line 4-4 of (FIG. 3 including a shock tube arrangement not shown yin FIG. 3; and

(broken away for lthe sake of illustrationin FIG. il).

Thus, with the current I flowing in a longitudinal' direction through ionized gas 3, the potential gradient E is alsolongitudinally directed, as shown. Assuming that the ionized gas, i.e. plasma, constitutes a near perfect electrical conductor, substantially all of the current I ows along the surface of the plasma 3 and, furthermore, this produces a magnetic eld represented by the circular flux lines B which surround the plasma 3i in the manner illustrated. Y

In accordance with the'well known pinch effect phenomenon, the magnetic field B functions to `constrict plasma 3 in such a mannerthat the gas particles are force-d inwardly toward the axis 5 of discharge tube 4, the constricting force being proportional to the square of the magnitude of the current Il. Consequently, the greater the magnitude of the current built 'up through the plasma, the greater the acceleration of the gas particlesa-nd the greater the final velocity or kinetic energy attained by them. It is thus seen that it is advantageous to reduce the inductive and transit time delays in the buildup .of current through the plasma in the shock tube.

FIlhe apparatus of the present invention produces these advantageous results.

Moreover, in accordance with the principles illustrated in FIG. 1, the gas particles are accelerated toward the central axis 5 of the discharge tube 4 and are, therefore,

removed 4frorrrcontact with the inner surface of the dis-v radiant energy in the form of light.

While the ygeneral principles outlined above in con- `nection with FIG. 1 have been previously employed dor experi-mental purposes in investigating the propertiesy of gaseous materials at high temperatures, there has been no known arrangement by which `a superfast pinch is achieved which imparts kinetic energy levels to the gas particles corresponding to temperatures in the thermonuclear range. In accordance with the apparatus of the present invention described below, a superfast pinch may be readily achieved ior imparti-ng the desired kinetic energy to the particles of an electrically conductive gas.

An arrangement `for achieving a superfast pinch in accordance `with the principles of the invention is illustrated in FIGLZ in which a discharge tube 6 is arranged to receive an electrically conductive gas from a source fof ionized Igas 7 via the conduit 8. Discharge tube 6 has a pair of electrodes 9 and 10' by means of which high density current pulses may be passed through a plasma within the discharge tube. One of the electrodes, namely, electrode 10,' may be directly connected to the center of a circular capacitor plate 11. A triggered switch` 12 is connected to the center of a circular capacitor plate 13 in a position adjacent the other electrode 9. A suitable dielectric material (not shown) may be placed between circular capacitor plates 11 and 13y and a high voltage supply 14 is connected across the capacitor' plates to charge them to aV sucient-ly high ylevel to produce a high density current liow through the discharge tube 6, thereby to produce a superfast pinch in the plasma contained therein.

A triggering electrode :of switch 12 is held at a potential Ilower than that of plate 13 bymeaus of a voltage divider comprising a pair of resistors y15 and 16 connected in series between high voltager supplly14 and ground. More specically, the triggering electrode of switch 12 is held at a potential which is suliiciently low to prevent a discharge between capacitor plates 11 and 13 whereby they are yfully charged. However, upon application of a voltage pulse to the triggering electrode ofswitch 12 via a terminal 17 and a capacitor `18, the potential gradient between capacitor plate 13 and .electrode 9 is increased to theV dielectric breakdown level, as a result of which capacitor plates 11 and 13 discharge through discharge tube 6. Due to the fact that discharge tube 6 is positioned symmetrically with respect to the Y f v Therefore, to obtain optimum resul-ts, all of the energy to -be transferred to the ga-s must be stored by thecapacitor within a distance Ifrom discharge or pinch tube i6 equal v where c=ce1/2 which is the velocity lof light in the dielectric A(if any) surrounding the pinch tube. The result lis that the ent-ire capacitor storage `facility dor use in rapidly establishing the desired high density current thro-ugh the dischargertube must he contained Within a predetermined dfi-stance yirom'the discharge tube, determined in the mathematical manner presented above.

mounting the discharge tube in a centrally located position with respect to the 'capacitor configuration.

FIG. 2 4illustrates one arrangement in accordance with` Ithe .invention lin which discharge tube ispositioned in a centrally located position with respect to circular capacitor plates 11 and 13 and, as shown therein, the tube is aioaoss mounted .along the axis of symmetry of the two plates. Hence, .the energy arriving vat the discharge tube is propagated toward the tube yfrom all directions yalong the capacitor plates. The result is that a large energy :storage tacility may be included within the maximum permissible distance .from .the discharge tube 16. In addition, since no other yelectrical connections are requ-ired between the capacitor plates Il and i3 and electrodes 9 .and It) of discharge tube `6, the indue-tance of .the 4arrangement is held to a minimum so that a short rise time of la current pulse through the discharge -tube results.

As noted previously, the pinch eiect occurring within the discharge tube 6 is observable .and may be recorded optically by means of .a :suitable camera. It should also be noted that since the gas particles .are driven inwardly away from .the Iwalls of the discharge, tube 6,- .a hot dense plasma may be `achieved without deterioration of the discharge tube walls. Suitablemagnetic iield gener-ating coils may be wound around the discharge tube for sustaining t-he hot dense plasma away from the walls of the discharge tube, or the .arrangement may be employed for confining .a plasma through .the use of microwave energy shown and described in the copending application of Erich S. Weibel, entitled Gas Conining Method and Apparatus, tiled ianuary 15, 1958, Serial Number 709,- 122. However, since the present invention is directed to a new and improved apparatus for achieving a super- -fast pinch without reference to mechanisms =for sustaining the hot gas plasma over an extended period of time, further -description `of means for sustaining the conned gases is not deemed necessary.

A preferred embodiment for'imparting high kinetic energies to the particlesv of `a gas :by means of the pinch effect is illustrated in FGS. 3-5 in which `a pair of coaxial-ly disposed cylindrical capacitor plates 20 and 21 are adapted to be discharged through .a cylindricallyshaped discharge tube 22 mounted therebetween. The outer cylindrical capacitor plate 2li may be connected to ground with the inner cylindrical capacitor plate 2l being charged to a high potential, such as la million volts, from a high voltage supply 23 (FIG. 5). The high rvolt- -age supply 23 may comprise any conventional apparatus for establishing potential levels of the .order of l06 volts, such as a voltage multiplying circuit. The outer and inner cylindrical plates *Ztl* and 2l, respectively, `are constructed of a suitable electrically conductive material such as steel with the ends of the outer cylindrical plate 20 being sealed as, Vfor example, by `a dielectric end piece 24 anda ring 25.

Between the cylindrical plates Ztl and 2l there may be wound a layer 26 of dielectric insulating material such as the material lcommonly identified as Mylar. Layer 26 should preferably extend beyond the ends of the inner cylindrical plate 21 so as to minimize discharge of the capacitor through creepage of electrical currents along the .surface of the dielectric 26. In .a similar means in the regio-n of the discharge tube Z2 (FIG. 4), the dielectric layer 26 may be extended to minimize current creepage. lFurthermore, to further minimize the possibility of current creepage and undue voltage breakdown, the space around discharge tube Z2 wherein very high potential gradients are established is surrounded by .a cylindrically and serrated or wavy-shaped electric insulator 26A which is preferably made of .a ceramic material. In connection with the manner that insulator 26A helps prevent voltage breakdown, it should be mentioned that due .to the high temperatures involved, electrode 3l) evaporates :somewhat and the resulting metal particles would ordinarily become deposited on the surfaces common Ito capacitor plates 20" and 2l in the area of the discharge tube. This would ultimately lead to a voltage breakdown `and the insulator prevents this from occurring. Actually, the serrations. or waves of insulathan the potential of the inner plate 2l.

1tor 26A are very much larger than shown in lFIG. 4 so that while metal particles will be deposited Ion the insulator, shadow `areas Iwill exist thereon Where the particles cannot penetrate rso that the integrity of the spiace relative to vol-tage breakdown .is maintained.

The inner cylindrical plate 21 may be closed at one end to receive an electrical `connection post I27 to which high voltage supply V23 is connected. The post 27 may extend through the end of the outer cylindrical plate 2B', but mus-t be insulated therefrom. In order to enhance the maximum potential gradient level to lwhich the capacitor pla-tes 2li .and 21 may be charged without breakl down, a source of :dielectric gas 28 such `as the chemical compound SFS may be connected to till the chamber between outer Vand inner cylindrical plates 2li and 2l, respectively. The possibility of break-down between the capacitor plates is minimized still further due tothe tact that the surfaces of the plates that .face each other are smooth. Accordingly, by means of high voltage supply 23, inner cylindrical capacitor plate Ztl may be brought to 4a high poten-tial llevel with respect to outer cylindrical capacitor .plate 20.

The discharge tube 22 is positioned between. the outer and inner cylindrical capacitor plates 2li and Z1, respectively, in a region substantially equidistant from the ends of the cylinders. Thus, the storage capacity of the plates 20 and 21 is symmetrically disposed with respect to the location of the discharge tube 22 which is preferably constructed of a transparent material such as quartz or sapphire to enable a visual or optical inspection of the phenomena occurring within. As may be best seen in FIG. 4, at the outer end of the `discharge tube 22, a metallic ring electrode 29 may be dinectly connected to the outer cylindrical capacitor plate 26. At the inner end of the discharge tube 22, an electrode 30 is spaced apart from a novel triggered switch assembly generally designated 31, a new type of triggered switch being needed because of the particularly thigh voltage levels and relatively small spacings involved herein.

More specifically, conventional trigger gaps are reliably triggered by applying a trigger pulse whose amplitude is greater than the static breakdown of the gap, the pulse being applied directly `from a hydrogen thyratron or from a step-up pulse transformer. However, due to the very high static breakdown voltage that is being used herein, hydrogen thyratrons are impractical and pulse transformers unsuitably large and complex. The triggered gap used in triggered switchassembly Slt vfurnishes reliable triggering and meets satisfactory timing requirements While requiring trigger amplitudes that are less than the static breakdown voltage. The triggered switch is directly connected to the inner cylindrical capacitor plate 2l and is adapted to provide an electrical connection between the inner plate 2l and the electrode Sil when actuated.

Triggered switch assembly 31 comprises a trigger electrode 32A coaxially disposed Within a cylindrical metallic ring 32B connected to the plate 21. A voltage divider comprising a pair of resistors 3.3 and 34 is connected between high voltage supply 23 and ground with the trigger electrode 32A being connected to the junction point 35 between resistors 33 and 34. `By a suitable proportioning of the resistors 33 and 34, the trigger electrode 32A may be sustained at a desired potential less By way of example, if the potentialv of inner plate 21 is 106 volts,

it has been found that a suitable potential for the trigger electrode 32A is one that is equal to four-fifths the `potential of the inner plate 21 or 8X105 volts. Thus, there is established in the region of the inner discharge tube electrode 30, a potential .gradient that is insuihcient to breakdown the dielectric between triggered switch 31 and electrode 30.

By means of a tubular triggering condenser 36 (FIG. 5), a positive going impulse may be applied to the trig- 7 gering electrode 32A to raise the potential gradient'in the region of electrode Sti to a level at which an arc discharge is instituted between electrodes 3d and 32A to connect electrically the charged inner capacitor plate 21. to the electrode Si) and thereby produce the current flow through tube 22. The manner in which the positive going pulse is applied to the trigger condenser 36 to institute the discharge between capacitor plates 20 and 21 is described in detail below.

in the operation of the arrangement of FIG. 5, a desired gas such as deuterium or tritium is introduced conduit .Tr-9., A gas outlet conduit 4d may be opened to the atmosphere by means of a, bleeder valve 41 to flush i the shock tube 37 free-of impurities.V When the vbleeder valve 4-1 is closed, gas input source SSFpreferably es-y --and the shock tube 37 is lilled with gas from gas input `into a shock tube 37 from a gas input source 38 via a.

source 38, a sequence timer 4t2=may be arranged to actuate a shock generator 43v connected between the sequence timer and shock tube 37. Shock tube generator 43 may be of any conventional form which is capable of establishing a shock wave within shock tube 37 which travels toward discharge tube 22. A detailed description of a suitable shock generator may be cfoundy vtriggered swito 31 described in detail above which receives a pulse from the sequence timer 42. As noted previously, the action of a shock wave traveli ing along a gas-filled tube functions to ionize and propel the gas particles at the interface between the wave and `the gas. Thus, the gas particles may be accelerated to kinetic energy levels corresponding to temperatures of the order of 105 Kelvin Within the shock tube 37. The outer end of discharge tube 22, adjacent ythe ring electrode 29 .is apertured and `formed to receive a centralv core of the gas propelled along the shock tube lE57 by the shock Wave. For simplicity of designation, the open end of discharge tube 22 is sometimes referred to as a fcookie cutter. The advantage in selecting the central core of the propelled gas is that the central core is substantially freer of impurities than the portions of the gas propelled along the sidewalls of the shock tube 37.

As soon as the electrically conductive gas is driven fully into the discharge tube 22 by the shockwave, the sequence timer 42 applies a pulse to a switching tube 44 which is connected between the tubular outer plate of the triggering condenser 36 and ground. The sequence timer 42 may comprise a delay line of a suitable length. which applies a pulse to the tube 44 lwhich is delayed by a pnedeter-mined extent with respect to the pulse applied to the shock generator 43 corresponding to the time required for the shock -wave to travell the length of the shock tube 37. In response to said pulse, they tube 44 .res and thereby shorts the louter plate of condenser 36 to ground.

Since, :as is shown, this outer'plate of triggering condenser 36 is normally held Iat a charged potential level t by a trigger voltage supply 45, which may be of the order of 250 kilovolts, the sudden connection of the tubular plate of the triggering condenser to ground causes a pulse to be applied to the junction point 35 whose magnitude is the voltage to which the tubular outer plate is charged, namely 250 kilovolts. The same pulse is therefore Iapplied to the triggering electrode 32A and, as a result of the increased voltage existing between electrode 32A and electrode St), the dielectricv between the inner discharge tube electrode 30 and the triggering electrodel 32A breaks down and this breakdown shifts immediately to the main gap region so as to initiate the discharge ot the capacitor plates 20 and 21 through the plasma within the discharge tube 22. More specifically, the current ows from capacitor plate 21 through triggering switch assembly 31 to electrodeltl and from this electrode the current flows through the plasma in discharge tube 22 to electrode 29 whereat the current enters capacitor plate 2t). A current discharge does vnot occur latany points between capacitor platesv 2d and 21 other than through discharge-tube 22. Since the discharge tube 22 ifs-directly Through the configuration of the arrangement of FIGS.

3-6 in which the capacitor is symmetrically'disposed with respect to the discharge tube 22, a maximum energy transfer may be `achieved lduring a short interval such as .01 microsecond. In addition, since the ydischarge tube 22 isv directly connected -between the plates20 and 21 during the discharge in-terval, lead lines or bus bars are avoided so that the effects of inductance are minimized with the result that a fast rise time of the current pulse may be achieved. Furthermore, even though the capacitor plate 21 is maintained at extraordinarily high voltages, such as l()Ei volts, itis surrounded bythe grounded capacitor plate 20 so that there is little hazard in the operation of the mechanism Iand corona discharge effects are reduced to a minimum.

A suitable `camera (not shown) of either optical or electronic character may be positioned adjacent the walls yof the discharge tube 22 :for recording the phenomena of the pinch elfect occurring within the discharge tube. As noted previously in connection with the discussion of the `apparatus of FIG. 2, stabilizing magneti-c fields or suitable microwave contning techniquesmay be employed -to sustain the pinched gas, if desired.

vIn one workable embodiment of the invention constructed Afor the purpose of investigating gas thermodynamic phenomena, the inner cylindrical capacitorpl-ate 21 had la length, L1=117 cm. and a radius, R1=18.7 cm. The dielectric layer 26 was of a thickness, h=1.27 cm. and la dielectric `constant 6:3. The discharge tube 22 had a Ilength of 2.54 cm.,r :and an inner radius of 0.635 ern. The capacity of the plates 20 and 21 equalled C 287() mmfd.

is suiciently large to accelerate the gas particles of `a.

plasma to kinetic energies well within the desired range.

Although there have been described above and illustrated `in the drawings particular arrangements of the invention for expediting the attainment of a high current density discharge of a capacitor through a discharge tube for the purpose of imparting kinetic energy to gas particles in accordance with the pinch effect, it will be appreciated that the invention is not limited to the specific illustrative arrangements.v Accordingly, iany modifica-v 9 tions, variations or equivalent arrangements falling within the scope of the annexed claims should be considered to be a part of the present invention.`

What is claimed is:

1. Gas heating apparatus comprising: a pair of electrically charged cylindrical capacitor plates coaxially arranged one inside lthe other, said plates having aligned orifices therethrough located substantially equidistantly from -their ends; a current discharge tube including an open-ended cylindrically-shaped body member enclosed by a rst electrode `at one end and having an annular second electrode mounted on the other end, said discharge tube being disposed between said capacitor plates and mounted to said outer plate in such `a manner that the open annular electrode end of said tube lis in alignment with the orifice of said outer plate; meansfor injecting an ionized gas of known characteristics through said outer plate orifice and into said discharge tube; and triggeredy switch means coupled to said means and to said capacitor plates, said switch means being operable to discharge said capacitor plates through said discharge tube, whereby apinch eiectis produced -by which high kinetic energies are imparted to the ionized gas particles.

2.. The apparatus defined in claim l wherein said means for injecting ionized gas into said discharge tube includes a shock tube containing the gas coupled to said discharge tube through the associatedv orifice, meansr'for establishing a shock wave within said shock tube which ionizes the gas contained therein and drives said gas into said discharge tube, and means coupled between said lastnamed means and said triggered switch means land operable in response -to said shock wave to trigger said switch means to discharge said capacitor plates.

3.l The apparatus deiined in claim 1 wherein said triggered switch means includes a timer device coupled to said means and operable in response to the injection of gas by said means to produce a triggering voltage pulse when said gas has been driven into said disch-arge tube; voltage divider apparatus connected between said capacitor plates for dividing the Voltage between said capacitor plates resulting `from the charge thereon in la predetermined ratio; a switch assembly including a cylindricallyshaped electrode mounted on said inner capacitor plate for electrical connection thereto and in alignment with the orifice through said inner plate, anda probe electrode connected at one end to `said voltage divider apparatus in such a manner as to be at a different potential than said inner plate and extending at the other end through said cylindrically-shaped electrode toward the first electrode of said discharge tube; and means for producing voltage pulses coupled between said voltage divider apparatus and said timer device, said means being operable in response to said triggering voltage pnlse to apply another voltage pulse to said voltage divider apparatus to increase the potential on `said probe electrode to substantially the potential of said inner capacitor plate, whereby said capacitor plates rapidly discharge through said switch assembly 'and discharge tube to produce said pinch effect.

4. Gas heating apparatus comprising: a pair of electrically charged cylindrical capacitor plates coaXia-lly arranged one inside the other, said plates having a pair of aligned orifices therethrough located substantially equidistantly from its ends, a current discharge tube including an open-ended cylindrically-shaped -body member enclosed by a first electrode at one end and having an annular second electrode mounted on the lother end, said discharge tube being disposed Vbetween said capacitor plates and mounted to said outer plate in such a manner that `the open annular electrode end of said tube is in alignment with the orifice through said outer plate; a shock tube containing a gas of known characteristics coupled to said discharge tube through the orifice of said outer plate; means for establishing a shock Wave Within said shock tube which ionizes the gas contained therein and t l0 drives the gas into said discharge` tube; a timer device coupled` to `said means and operable in response `tothe injection of` gas by said means to produce'a triggering voltagepulse when said gas has been driven into said discharge tube; voltage divider apparatus connected between said capacitor plates for dividing` the voltage between said capacitor plates resulting` from the charge thereon in` a predetermined ratio; a lswitch assembly including a cylindrically-shaped electrode mounted on said inner capacitor plate for electrical connection thereto and in align- Iment with the orice through said inner plate, and a probe electrode connected at one end to said voltage divider apparatus in such a manner as to be at a different potential than said inner plate and extending at the other end through said cylindrically-shaped electrode toward the first electrode of said discharge tube; and means for prol ducing voltage pulses coupled between said voltage divider apparatus and said timer device, said means being operable in response to said triggering voltage pulse to apply another voltage pulse to said voltage `divider apparatus to increase the potential on said probe electrode tosubstantially the potential of said inner capacitor plate, whereby said capacitor plates rapidly discharge through `said switch 4assembly and discharge tube to produce a pinch eiect by which high kinetic energies are irn-` parted to the ionized gas particles.

5. Apparatus for imparting kinetic energy to ionized gas particles including the combination of a capacitor hav-` ing at least two coaxially disposed cylindrical plates, a discharge tube disposed between the cylindrical plates in a centrally located position, means introducing ionized gas into the discharge tube, a high voltage source coupled to the capacitor for charging the capacitor to :a level at which a pinch effect is produced in the ionized gas when the capacitor is discharged through the discharge tube, and means -selectively discharging the charged capacitor through the discharge tube to create a pinch effect in which high kinetic energies are imparted to the ionized gas particles.

6. A non-adiabatic gas heating arrangement including the combination of a discharge tube, a first `electrode mounted at one end of the discharge tube, a second electrode mounted at the other end of thedischarge tube, a rst cylindrical capacitor plate mounted adjacent the first electrode in a position in which the ends of the cylindrical plate are e'quidistant from the discharge tube, a triggered switch connected between the first cylindrical capacitor plate and the tirst electrode, a second cylindrical plate coaxially arranged with respect to the first cylin-drical capacitor plate and directly connected to the second electrode ina position in which the discharge tube is equidistant from each end of the -second cylindrical plate,

means introducing electrically conductive 'gas into the i discharge tube, means connected to the first capacitor plate for establishing a potential gradient between the 'irstand second capacitor plates representing an energy storage sufiiciently large to create a pinch eiect in the -gas fwithin the discharge tube when the capacitor is discharged therethrough, and means applying a voltage pulse to Ithe triggered switch for electrically connecting the iirst cylindrical capacitor pla-te to the first electrode to discharge the capacitor through the discharge tube whereby a pinch effect is established in which high kinetic energies are imparted to the ionized gas particles.

7. Apparatus in accordance with claim 6 in which the means for introducing ionized gas into the discharge tube includes a shock tube connected to the discharge tube, and means for establishing a yshock wave Within the shock tube which ionizes the gas contained therein and drives the gas into the discharge tube.

8. A 4non-adiabatic gas hea-ting arrangement including fthe combination of a discharge tube, a first. electrode mounted at one end of the discharge tube, a second electrode mounted at the other end of the discharge tube, an inner cylindrical capacitor plate mounted adjacent the triggered switch connected` 4between the inner-cyliridricalcapacitor plate and the irst electrode, an outer cylindrical plate coaxially arranged with respect to the inner cylindricai capacitor plate and directly connected to the second electrode in a position in which the discharge tubeisequidistant |from eachend of the outer cylindrical plate, means introducing electrically conductive gases into the discharge tube, means connected to the inner capacitor plate'for. establishing a poten-tial gradient between the inner and outer capacitor plates representing anV energy storage sutiiciently large to create a pinch effect in the gas Within the ldischarge tube when the capacitor is discharged therethrough, and means applying a voltage pulse. to the triggered switch for electrically connecting the inner cylindrical capacitor plate to the irst elect-rode to discharge the capacitor through the dischange tube Iwhereby a pinch eitect is established in which high kineticenergies are imparted to the ionized gas particles. Y

9. Apparatus in accordance with claim 8 in which the includes a shock tube connected t-o the discharge tube, and means for establishing a shock Wave ywithin the shock tube which ionizes the gas con-tained therein and drives the -gas into the dischar-ge tube. Y s

10. Apparatus for heating a gaseous material including vthe combination of an open-ended discharge tube, a capacil the discharge tube in a predetermined time relationship with respect to the generation of a shock wave by the shock generator .to produce a pincheffect in the gaseous material within the discharge tube. I

l1. A non-adiabatic ygas heating arrangement including the combination of a discharge tube, a tirst electrode lof 4the cylinl triggered switch connectedbetween the inner cylindrical v 'means for introducing ionized gas into the discharge tube v 'by the shock'. generator toproduce a pinch effect in the mounted at one end of the discharge tube, a second electrode mounted at the other end of the discharge tube, an

inner cylindrical capacitor plate mounted adjacent the irst electrode in a position in which the endsfof the cylindrical plate are equidistant from the discharge tube, a

capacitor` plate and the first electrode, an outer cylindrical plate coaxially arranged with respect tothe inner cylindrical capacitor plateand directlyl-connected-to the second electrode in a position in Iwhich the discharge tube is equidistan-t from each end lof the outer cylindrical plate,l a shock tube connected to the discharge tube, means intro-r ducing a gaseousr material into the shock tube, a yshock generator connected to the shock tube for generating a sufficiently large to create a pinch effect in the gas within the discharge tube when the capacitor is discharged there# through, `and means applyinga Voltage pulse to the tniggered switch for triggering a discharge of the capacitor1 through the ydischarge tube in a predetermined time rela tionship with respect to the generation ot a shock wave gaseous material within the discharge tube.

References Cited in the le of-this patent UNITED STATES PATENTS 2,728,877 Fischer Dee 27, 1955 2,911,567 Fischer Nov. 3, 1959 s s FOREIGN PATENTS t 1,022,711 Germany Jan. 16,

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1. GAS HEATIG APPARATUS COMPRISING: A PAIR OF ELECTRICALLY CHARGED CYLINDRICAL CAPACITOR PLATES COAXIALLY ARRANGED ONE INSIDE THE OTHER, SAID PLATES HAVING ALIGNED ORIFICES THERETHROUGH LOCATED SUBSTANTIALLY EQUIDISTANTLY FROM THEIR ENDS; A CURRENT DISCHARGE TUBE INCLUDING AN OPEN-ENDED CYLINDRICALLY-SHAPED BODY MEMBER ENCLOSED BY A FIRST ELECTRODE AT ONE END AND HAVING AN ANNULAR SECOND ELECTRODE MOUNTED ON THE OTHER END, SAID DISCHARGE TUBE BEING DISPOSED BETWEEN SAID CAPACITOR PLATES AND MOUNTED TO SAID OUER PLATE IN SUCH A MANNER THAT THE OPEN ANNULAR ELECTRODE END OF SAID TUBE IS IN ALIGNMENT WITH THE ORIFICES OF SAID OUTER PLATE; MEANS FOR INJECTING AN IONIZED GAS OF KNOWN CHARACTERISTICS THROUGH SAID OUTER PLATE ORIFICE AND INTO SAID DISCHARGE TUBE; AND TRIGGERED SWITCH MEANS COUPLED TO SAID MEANS AND TO SAID CAPACITOR PLATES, SAID SWITCH MEANS BEING OPERABLE TO DISCHARGE SAID CAPACITOR PLATES THROUGH SAID DISCHARGE TUBE, WHEREBY A PINCH EFFECT IS PRODUCED BY WHICH HIGH KINETIC ENERGIES ARE IMPARTED TO THE IONIZED GAS PARTICLES. 